Metal eating bacteria
I was reading the headlines on CNN this morning, and this one grabbed my eye. The gist of the article is that researchers from Dalhousie University, in Halifax, Nova Scotia, examined some sediment brought up from the wreck of the Titanic. Scientists have been visiting the wreck site in the North Atlantic for about 25 years, since it was initially discovered by Robert Ballard in 1985. Surveys of the wreck were initially accomplished by remote observation, but within a year or two, manned submersible were visiting the site and retrieving artifacts. The condition of the wreck significantly increased our understanding of how the tragedy occurred, however the common consensus among scientists was that access to the site should be restricted to maintain it in as pristine of condition as possible.
Ballard’s initial survey of the wreckage indicated that significant corrosion of the steel superstructure has occurred over the past 100 years. The exposed structure is covered with growths termed “rusticles,” which are large, icicle-like formations of rust. These structures turned out to be teeming with biofilms of bacteria, which were recovered and brought back to the surface. When examined in the laboratory, it was found that these organisms very readily grew on and began to break down any metal structures that there were introduced to. The researchers at Dalhousie University have conjectured that the wreck of the Titanic will degrade into a rust-colored patch on the ocean floor within the next 30 years, and little physical evidence of the tragedy will remain after that point.
So here’s a bonus opportunity: based on what we know about microbial growth (hint: Chapter 6,) what can we surmise about what the scientists at Dalhousie had to consider when trying to growth these bacteria in the lab? There are several things, so please comment here!